Modular system for putting together different sized filter elements

ABSTRACT

A modular system for putting together different sized filter elements, especially filter elements having different lengths, more particularly filter devices for hydraulic fluids, comprising a support tube that defines an inner cavity in the corresponding filter element, said tube being surrounded by a filter mat that is substantially cylindrical and that matches the different dimensions and having passages to let the fluid pass through. The filter elements also contain at least one coupling member enabling connection on the end side of a corresponding support tube to an additional support tube having a location on the end side for interacting with and locking on the coupling member. Each coupling member is embodied as an attachment plug element with a crown consisting of interspaced tabs extending in axial direction and hooks for snapping on the location of the attached support tube.

The invention refers to a modular system for the assembly of filterelements of different structural sizes, in particular, constructionlengths, namely with filter devices for hydraulic fluids, with asupporting tube, which defines an interior cavity of the pertinentfilter element, a supporting tube with filter mat, which has passages topermit the fluid to pass through, and whose jacket is formed by circularrings, arranged at mutual intervals from one another, which are carriedby the vanes of a star-shaped profile body, extending axially in theinterior of the supporting tube, and with at least one coupling piece,which makes possible the end connection of one pertinent supporting tubeto another supporting tube, which has a holder, intended for an end, forthe interaction and locking with the coupling piece, which is shaped asa plug element with a ring, which consists of fingers, that extend in anaxial direction at mutual intervals, and which has hooks formed at theend to snap on at the holder of the following supporting tube.

A system of this type is already known from EP 0769 317 A1. The goal ofthe invention is to create a system of the aforementioned type, which ischaracterized by particularly good operating characteristics, namely,improved structural strength of the assembly of coupled supportingbodies.

The goal of the invention is to create a modular system of the typeunder discussion, which is easy to handle and inexpensively produced.

In a modular system of the initially mentioned type, this goal isattained in accordance with the invention in that the ring, consistingof fingers, oriented to the vanes of the profile body, has widened gapsbetween adjacent fingers, and these gaps make possible the engagement ofthe ends of the vanes.

Owing to the shape of the ring, consisting of fingers carrying snaphooks, in accordance with the invention, the ends of the vanes of theinterior profile bodies, which engage the gaps between the fingers whenthe connection is set up, come into correct position relative to oneanother immediately. A full support surface, extending over the entirecross section of the profile body is therefore available, by means ofwhich the axial forces acting on the filter element during operation canbe transferred, so that the desired high structural strength of theassembled filter element is produced.

With the modular system in accordance with the invention, supportingtubes with a holder, intended for one end, for the interaction andlocking with the coupling piece can be used. Likewise, supporting tubes,which have a holder for the interaction and locking with a couplingpiece at each end, can be taken into consideration as components of themodular system. Moreover, supporting tubes with only one coupling piece,affixed to the end and supporting tubes with a coupling piece affixed toeach of its two ends are provided.

Also, a coupling piece in the form of a special adapter can be provided,which is intended to interact and lock with a holder on each of thesupporting tubes to be connected to one another.

The modular system, in accordance with the invention, thus opens updiverse combination possibilities for the assembly of filter elements ofthe required size.

The invention is explained in detail below, with the aid of embodimentexamples represented in the drawing:

FIG. 1, a longitudinal section of the upper end of a filter element,depicted partially broken off, with a bypass valve used in the interiorof its supporting tube;

FIG. 2, a schematic representation of supporting tubes, in part withvarious structural lengths, and of coupling pieces, by means of whichthe supporting tubes are affixed one to another;

FIG. 3, a longitudinal section of a coupling piece, shaped on one end ofa supporting tube in the form of a plug element, which is depictedbroken off an on an enlarged scale;

FIG. 4, a side view of the plug element of FIG. 3;

FIG. 5, a lower view of the plug element of FIGS. 3 and 4, shaped on theend of the supporting tube;

FIG. 6, a partial longitudinal section of a finger of the plug elementof FIGS. 3 and 4, which is depicted broken off, with a snap hookengagement with a ring on a plug holder of another supporting tube; and

FIG. 7, partial view of the plug element, which is depicted broken offand enlarged, seen in the observation direction designated by X in FIG.5.

FIG. 2 shows, in schematic representation, components of the modularsystem, in accordance with the invention. This system comprises parts inthe form of supporting tubes of various structural lengths with couplingpieces and/or coupling-piece holders on the ends, injection-molded frompolyamide plastic (PA 6), and coupling pieces in the form of adapters,separated from the supporting tubes; said adapters are designated byreference number 1. Reference number 3 designates supporting tubes of ashort structural length with a coupling piece 5 on one end. Supportingtubes of longer structural length and with a coupling piece-holder 7 onone end are designated by reference number 9. On the other hand,supporting tubes of somewhat shorter structural length and a couplingpiece 5 on one end and a coupling-piece holder 7 on the opposite end aredesignated by reference number 11. Reference number 13 characterizessupporting tubes and in contrast, a greater length with a coupling-pieceholder 7 on the end.

FIG. 1 shows, in larger representation, the supporting tube 3,associated with the upper end of a filter element 15 and surrounded bythe upper part of the pertinent filter mat 17. A lid 19, which forms theupper seal and which is also injection-molded from the same plastic asthe supporting tube 3, overlaps the upper edge of the filter mat 17, iswelded with the end edge of the supporting tube 3, and forms a centralinlet 21 for the fluid entry to a bypass valve 23, integrated with theinterior cavity of the supporting tube 3, whose valve body 25 normallyprovides a sealing on the lid 19, under spring tension against the edgeof the inlet 21.

As can be seen from FIG. 1, the coupling piece 5, formed on the end ofthe supporting tube 3, is shaped as a plug element in the same way asthe coupling pieces 5 of the supporting tubes 11 and the coupling pieces5 formed on both sides on the adapter 1; the plug element is formed froma circular ring, consisting of fingers 27, which extend axially and, inpart, have various widths, of which the wider finger 27 are providedwith snap hooks 29, which project radially to the outside (see FIGS. 3to 6).

As can be seen most clearly from FIGS. 2 and 6, the jacket of thesupporting tubes 3, 9, 11, and 13 consists of a series or rings 31,which are arranged at axial intervals from one another, so that passagesare formed to permit the fluid to pass. As FIG. 5 shows, the rings 31,in supporting tubes 9, 11, and 13, are carried by the ends of the vanes33 of a star-like profile body 35, which extends axially in the interiorof the supporting tube in question. In the short supporting tube 3, asshown in FIG. 1, the bypass valve 23 forms, with its base 38, a part ofthe interior profile 35—more precisely, this base 38 forms the limit ofa recess in the interior area of the vanes 33, in which the bypass valve23 is held.

The interior side of the tube jacket of the supporting tube in question9, 11, or 13 is used to form the coupling-piece holder 7—that is, as aholder for the inserted ring of the fingers 27 of the plug element,wherein the ring 37 on the end, defining the tube jacket has an axialextension, which is reduced in comparison to the other rings 31. Thelength of the fingers 27 of the plug element, measured by a shouldersurface 39 (FIG. 3) is dimensioned on the basis of the finger 27 in sucha way that the snap hooks 29, in the state of their insertion into theholder 7, snap behind the next ring 31, and the shoulder surface 39 isadjacent to the end ring 37 (see FIG. 6).

As can be seen, in particular, from FIGS. 3, 5, and 7, there are threeenlarged gaps 41 between adjacent fingers 27 of the ring, consisting offingers 27. These gaps 41 are oriented towards the radial vanes 33 ofthe interior profile body 35. The assembly of the plug element and theholder 7 ensures that the end surfaces of the vanes 33 of the interiorprofile bodies 35 and the adjacent supporting tubes are aligned and thuscorrectly positioned, so that axial forces are transferred fromsupporting tube to supporting tube via the interior profile bodies 35.As can be seen from FIG. 7, the fingers 27 on one of the widened gaps 41have lateral bevelings 43 as an insertion aid during the assembly of thecomponents.

As can be seen from FIG. 2, a variety of combination possibilities forthe formation of desired supporting tube lengths, perhaps with thebypass valve 23, integrated into the supporting tube, result with thecomponents of the modular system, in accordance with the invention. Thecoupling pieces in the form of the adapter 1, which have a plug elementwith a ring, consisting of fingers 27 on both sides, make possible themutual connection with opposing holders 7, whereas the supporting tubes3 and 11 with a coupling piece formed on the end are intended forinteraction with the end of a following supporting tube 9 or 13 shapedas a holder 7.

What is claimed is:
 1. A modular system for the assembly of filterelements of different structural sizes, comprising a supporting tubewhich defines an interior cavity of a filter element and carries afilter mat which has passages to permit fluid to pass through, and ajacket formed by a plurality of circular rings, arranged at mutualintervals from one another, which rings are carried by vanes of astar-shaped profile body extending axially in the interior cavity of thesupporting tube, and having a coupling piece which makes possible an endconnection of one supporting tube with another adjacent supporting tube,which has a holder intended for one end for interaction and locking witha coupling piece, which is shaped as a plug element with a ringconsisting of a plurality of fingers that extend in an axial directionat mutual intervals and that have a plurality of hooks formed on an endof said tube to snap on at the holder of the adjacent and waitingsupporting tube, wherein each of said rings consisting of fingers haswidened gaps between adjacent fingers which are oriented toward thevanes of the profile body whereby these gaps make possible theengagement of ends of the vanes.
 2. The modular system according toclaim 1, further comprising said supporting tube having a holder for theinteraction and locking with a coupling piece on each end of said tube.3. The modular system according to claim 2, wherein coupling pieces arearranged on a separate adapter which is provided for interaction andlocking with a holder on supporting tubes which are to be connected toone another.
 4. The modular system according to claim 3, whereinsupporting tubes with a coupling piece or a holder and with a base of abypass valve formed in the opposite end area in the interior of thetube, are provided.
 5. The modular system according to claim 2, whereineach supporting tube is shaped as a one-piece injection-molded articleof plastic.
 6. The modular system according to claim 2, whereinsupporting tubes with a coupling piece or a holder and with a base of abypass valve formed in the opposite end area in the interior of thetube, are provided.
 7. The modular system according to claim 1, whereineach supporting tube is provided with a coupling piece affixed to one ofits ends.
 8. The modular system according to claim 7, wherein couplingpieces are arranged on a separate adapter which is provided forinteraction and locking with a holder on supporting tubes which are tobe connected to one another.
 9. The modular system according to claim 7,wherein each supporting tube is shaped as a one-piece injection-moldedarticle of plastic.
 10. The modular system according to claim 7, whereinsupporting tubes with a coupling piece or a holder and with a base of abypass valve formed in the opposite end area in the interior of thetube, are provided.
 11. The modular system according to claim 1, whereina supporting tube is provided with a coupling piece affixed to each ofits two ends.
 12. The modular system according to claim 11, wherein eachsupporting tube is shaped as a one-piece injection-molded article ofplastic.
 13. The modular system according to claim 11, whereinsupporting tubes with a coupling piece or a holder and with a base of abypass valve formed in the opposite end area in the interior of thetube, are provided.
 14. The modular system according to claim 1, whereincoupling pieces are arranged on a separate adapter which is provided forinteraction and locking with a holder on supporting tubes which are tobe connected to one another.
 15. The modular system according to claim14, wherein each supporting tube is shaped as a one-pieceinjection-molded article of plastic.
 16. The modular system according toclaim 14, wherein supporting tubes with a coupling piece or a holder andwith a base of a bypass valve formed in the opposite end area in theinterior of the tube, are provided.
 17. The modular system according toclaim 1, wherein each supporting tube is shaped as a one-pieceinjection-molded article of plastic.
 18. The modular system according toclaim 1, wherein supporting tubes with a coupling piece or a holder andwith a base of a bypass valve formed in the opposite end area in theinterior of the tube, are provided.